Although lately, working with big databases and data files, more often enough the story ends more like "realize that the script does exactly the right thing, but $OTHERSCRIPT supplied broken data. (Junk in/Junk out principle)".

"I know what i'm doing! Look, what could possibly go wrong? All i have to pull this lever like so, and then press this button here like ArghhhhhaaAaAAAaaagraaaAAaa!!!"